Hydraulic motor or pump



April v1946- J. D. BUCHANAN 2,397,594

HYDRAULIC MOTOR OR PUMP Filed Jan. 6, 1945 2 Sheets-Sheet l 1 i .1; 3 219 4 5 1 @1 1 J /V 13 70 v w v J5 16 55 16 5239 8 J4 a? 5 a Z 1.6 ii? J419 17 13 F 1 D. .gUCH/J/VAN,

INVENTOR.

ATTORNEY.

April 1946. J, D. BUCHA'NA'N M 2,397,594

HYDRAULIC MOTOR OR PUMP Filed Jan. 6, 1945 2 Sheets- Sheet 2 w Pressure[319 4/.

WW 4 A l 57%7 fi s/must jfi'yufil I 1' I r ZID. fiucHA lA/w IINVENTOR.

ATTORNEY.

' whether inlet.

- plungers.

Patented Apr. 2, 1946 PAT HYDRAULIC Moron, on romp J. D. Buchanan,Burbank, Calif. Application January 6, 1945, Serial No. 571,631

I v Clainis. The invention relates to a *hydraulic'or fluid motor orpump of the. well-known type wherein therotor is" provided with a wobbleplate 'actuated by or actuating a series of plungers, de-

pending upon whether the device is employed as a motor or pump. Therotor of thedevice is provided with a rotary valve to control the fluidflow.;

In one type' of. wobbl 'plate' motor or pump, as

constructed heretofore, the rotary valve is in the.

form or a. channel on the periphery of the rotor, one side of thechannel lyin'g in aplane which is at rightangles' to thelongitudinalaxis of the rotor, the other'side of the channel being in the form of acurve to supply'the fluidpressure to or from theplungers in sequence.The disadvantage of this construction is that the side- 1 walls of thechannel are not symmetrical'as to their angular position with respect-tothe axis or the rotor, whereby the inclined side wall has a thrust onthe rotor.

I An obiect of the present invention is to avoid the above defect andthis is'accomplished by providing an improved rotary valve having aconstruction which reduces or to a large extent eliminates the lateralthrust on the rotor.

Another object of the invention is to reduce:

or substantially eliminate longitudinal thrust on the'rotor due to thelongitudinal thrust on the rotary valve and on the plungers associatedwith,

the wobble plate. This is accomplished by providing. stem end ofthe-rotary valve a piston area which ofisets the sum of the longitudinalthrust on the rotary valve and on the plungers, and by arranging at theother end of the valve a piston area-which oflsets the difference inthose thrusts. The casing is provided with'a pair of. passages either ofwhich may serve as in inlet when'the other is serving as 'an outletQsothat the direction of rotation may be reversed, The feature lastmentioned substantially balances the rotor for longitudinal thrust,regardless of one passage or the other is used as an For further detailsmay lie-made to the drawings, wherein:

- Figure l is a longitudinal sectional view through an'improved 'motoror pumpaccording to the Fig. 1 with same construction shown in the otherfigures with the addition thereto oifsprings for operating the Referringin detail to the drawings, the motor or pump 1 is of the well-knownwobble zplate lateral componentresulting in lateral or 'side.

time invention, reference wherein a wobble plate '2 is mounted on a ballbearing 3 suported on a bearing block 4 in a tilted position as'shown.The bearing blockA is secured by a keyli to the shaft 8 of the rotor I.o.

. Shaft 8- is supported in a bearing III in a cap and also ina bearing 9in. one end wall .10 of the casing l l and in a bearing I2 in acap I3 atthe other end 01 casing ll. I

by, or operates a series of plungers ll here, shown as six-in number,althougheanyothersuitable number may be used. Each of the plungers llslides in a bore such as I! which-extends parallel to the axis of shaftI. The casing is provided with a valve bore l8 and all oi the plungerably the piston bores l5 arearranged in pairs diametrically oppositeeach other so that the.

piston bores IS with the valve'borei6 may be drilled one pair at a timeand the. outer end of the passage may then be sealedoil by a plug ,asindicated at Ill. The plugs for the other two pairs of plunger boresareindicated in Fig. 3 at 20 and 2|.

The shaft 6 which controls the fluid pressgre to and exhaust from theplungers. ll. At one end of valve 22 the casing III is provided, with apassage 23 which end of valve 22 casing H is provided witha passage24adapted to serve as an outlet when 23 1 is an inlet,.and as an inletwhen 23 is, an outlet. 5 'According to the present invention, the, valve22 is provide'd with a pair 01' channels 25 and 26 each having sidewalls 21, 28 and 28, 80,, respectively, which are similarly inclinedwith respect to the longitudinal axisroftherotorl whereby side orlateral thruston the rotor l is, toa large extent, eliminated. v v v aThe two channels '2! and 26 are separated by the inclined wall 3| sothat each channel is always sealed oil from the other channel. In other5 words, it we start atthe top or channel 25 in Fig. 1 and follow aroundthis channel, we will arrive back at the starting point, and the same-istrue of channel as; This is further illustrated mane 1 developed view inFig. 4 wherein it isclearxthat if this figure were. rolled up into acylinder, the opposite ends of channel 25. as shown in this fig-. urewould be connected together, and the sarne. is true of channel 2|. a j

Opposite the passage 22, the rotor 1 has a dimeter ora reduced section22 which is smaller than the bore ii, the left sided the reduced section82 merging with a wall portion." which extends at right angles to theaxis-oiL-rotor 1. Around the reduced section" 22 is a chamber 24 whichcommunicates with the passage 23, and

ENT

The wobb1e plate 2, as wellness, is operated bores such as I! open intothe-bore l8. Prefercross passages like I! and I8 which connect the v isprovided with a rotary valve 22 may be an inlet or an'outlet and at theother It will be apparent thatvarious may be made in the inventionwithout departing.

groove 25 opens into this chamer at one side of rotor 1 where theinclined wall 21 intersects the straight wall 23 as indicated at 26. Theopening 2 35 thus 'maintalnsthe groove always income.

munication with the passage 22. V

The channel 28 is similarly constructed except thatitsinclined wall 30opens into the chamber 22 at a point 21, which is diametrically'oppositethe point 35. Chamber 2| always communicates I with the passage 24. 7

when passage 22 is serving as an inlet; fluid pressure in channel 2!exerts a lateral pressure 1 on wall 28 in one direction of an amountjust the same as that exerted on wall 21 in the opposite 1 direction,except forthe diflerence in the length of the lateral components'ofthese walls, due to ",the cut away portion 25 where channel opens 1intothe. chamber 24. In onedesign, it was found i ;that.-this?diflerenceis about ten percent (10%) which is permissible. The same considerationssage serves as an inlet. The rotor,therefore, is substantially balancedagainst lateral thrust regardless of which of the passages 22 and 24serves asaninletf' Each of the plunger passages like l1 and ,IIterminates'in a plunger port shown at I2 and I5 a,ao7,sa4 v V r 7 havinga stator with inlet and exhaust passages and a seriesiof plungers,-and acooperating rotor having a wobble plate, and having a rotary valvehaving a pair of peripheral channelscontrolling fluid supply to andexhaust'fi'om said plungers,

the improvement in said rotary'valve wherein said channels have sidewalls similarly inclined with respect to the axis of said valve tooffset lat- .eral thrust on said valve from fluid pressure at saidinlet.

2. ma wobble plate type of motor or pump havinga stator with inletandexhaust'passages and a series of lungers, and acooperating rotor havinga wobble plate and having a rotary valve having a pair of peripheralchannelscontrolling fluid supply to and exhaust from saidplunger's,

' the improvement which comprises a piston on apply towalls 28 and lflof'cha'nnel 22, whenpas,

m Fig. -2. the six ports being indicatedat u to st .-in Fig. 4. Thecenter linesof the plunger ports II to liilie in a plane which is atright. angles cated' by-the line 51in Fig. 4.v Also, as will be apparentfrom Fig. 1, and Fig. 4, that plane inl tersects-both of the channels 25and 28 whereby.

certain of the plunger ports. are -connectedto the inlet supply at thetime when other plunger;

ports are connected to the exhaust. .Also, one of the such ash is fullyopened to'the'inlet pressure at thetime that a diametricallyoppositeport is fully open to the exhaust. The channels '25 and 26' serveto'connect-the various plunger ports ii to 56 to the supply and'exhaust,

in the Opposite direction .on the left end of piston 28, which isprovided with anrannular area 29 'suflicient to counterbalance thosethrusts.

When passage 24 serves as an inlet, the longitudinal thrust onthe leftend of. valve 22 is in 'a directionto the right, over an areaequal tothe'diflerence in 'crosssectional'area of wall 3| m bore l6 and the areaof shaft s in bearing a while an equal :thrust on the rotor due to the:

pressure operated plungers I4 is tothe left. The

.' rotor shaft I is, therefore, balanced against lon-I the-pasgitudinal'thrust regardless of which of sages 22 and 24 is used asan inlet.

I'n.the modification showninfFig. 5, a com pression spring like may bearranged in each plunger bore 42 inorder. to urge each plunger saidrotorto offset longitudinal thrust onsaid rotor due to the sum of the thrustson said ro- 1 tary valve and on said plungers.

3. In a. wobble plat .type of motor or pump having a stator with inletand exhaust passagesand a series of plungers, and a cooperating rotorhaving a wobble plate and'having a rotary valve having a pairofperipheral channels controlling-.1 fluid supply to and exhaust fromsaid plungers,

the improvement insaid rotary valve wherein said channels have sidewallssimilarlyinclinedfj with respect to the axis of said valve to oflset soto the axis'of the-rotor 1, and this plane is indi-Q- lateral thrust onsaid valve from uid pressureat said inlet, and a; piston and shaft onsaid rotor at opposite ends of said rotary valve, said pistonoil'setting longitudinal thrust on said rotor dueto the'sum of thelongitudinal thrusts on said rotaryvalve and on said plungers, and thethrust on the difl'erenceinicross sectional area of said valve and saidshaftofisetting longitudinal thrust on said rotor due to said plungers,whereby said rotor issubstantially balanced for longitudinal and lateralthrusts forflow inone direction or they reverse directionthroughsaidpas:-

' sages.

, casing"having inlet and exhaust passages and 4-. In a wobble platetype of motor or pump, av

plunger ports, arotary valve in said casing, said valve having tworeversely inclined parallel channels of which one opens into one of saidpassages v at one side of said valve and the other channel opens intothe other passage at the other side of said valve. the centers of saidplunger ports lying in; a plan at right angles to the valve axis, saidplane intersecting one portion of one of said channels and anotherportion of. the other channel and said channels being constructed andarranged ,to" connect said plunger ports to supply 7 and exhaustinaprogressive manner. v 5. A wobble plate'motor or pump havingga sta Itor with inlet and exhaust passages and a series .of plungers, a bearingin saidstator, a cooperat ing rotor-having a shaft,.said rotor having awob- -ble plate on said shaft at one side of said bear- I ing and havinga rotary valve on said shaft at the other side of said bearing, saidrotary valve having a pair of peripheral channels controlling fluid like43 against the wobble plate 44. Otherwise, 7 the construction in Fig. 5,is the same as that described above. a

fromthe spirit of I the following claims. I claim:

. 1. Ida wobble plate type-of'motor or pump.

4 g improvements supply. to and exhaust from said, plungers, said inletcommunicating with th end of said rotary valve adjacent saidbearing,vthe,thrust of said plungers on said wobble plate beingeffective in one direction of said rotor, and the cross-sec;

tional area of said shaft being smaller than. the

cross-sectional area of, said rotary valve to pro-' vide a thrustintheopposite'direction whichoifsets said thrust of said plungers. j

. J, D.. 'B

